In order to minimize pollutants such as Nox, internal combustion engines typically include an exhaust gas recirculation (EGR) valve. The exhaust gas recirculation valve can be used to redirect a portion of exhaust gases to an intake conduit, such as an intake manifold, so that the redirected exhaust gases will be recycled.
Smith, U.S. Pat. No. 3,948,231 discloses a power and deceleration governor for automotive engines, that includes a butterfly type mixture control valve. In a first embodiment of the governor, the mixture control valve is actuated using a rack and pinion arrangement, driven by a diaphragm motor. In a second embodiment of the governor, the mixture control valve is actuated using a hydraulic cylinder. In a third embodiment of the governor, the mixture control valve is actuated using a clutch drive motor.
However, in all three embodiments disclosed in U.S. Pat. No. 3,948,231, the governor has a somewhat bulky structure, with an actuating shaft oriented generally transverse to a flow passage that contains the butterfly type mixture control valve, which could lead to packaging difficulties for engine applications in which space for such mechanisms is limited. In addition, all three embodiments rely on a vacuum system, that may not provide fast valve response. Thus, it is desirable to have an EGR valve that is both fast-acting, and compact in design.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.